A compressor which compresses gases and supplies the compressed gases to machines or the like connected downstream is known. As this compressor, there is a compressor in which a gas flow rate for a compressor body is adjusted by arranging an inlet guide vane (IGV) upstream and adjusting a degree of opening of the IGV.
In Patent Document 1, technology of appropriately controlling a degree of opening of the IGV and performing an optimum operation even when a performance difference occurs among a plurality of compressor bodies is disclosed as related technology.